This invention is particularly concerned with the use of electrical cables in field operations, where often many thousands of feet of electrical cable are laid out for the conduct of seismic geophysical operations. Field cables used in such operations are subject to damage by rodents or other small or large animals. In seismic operations, a high degree of insulation is required on the conductors because even minute leakages to the ground can cause considerable noise to be generated on the conductors that may even exceed the useful signals. Thus, it is imperative that such cables be adequately protected against rodent and other animal bite damage to the conductors. It is the intent and purpose of the instant invention to prevent any conductor damage caused by the gnawing on these cables by animals.
In the past, electrical transmission cables were usually suspended above ground in populated areas and supported by the ubiquitous, unattractive telephone pole or metal tower. The development of optical fiber technology has caused engineers and planners to supplant suspended cables with underground cable installation. Furthermore, in outlying regions, the cost and difficulty of stringing cable over rugged terrain requires that the cable be positioned on or below ground. The problem that occurs in each of the latter scenarios is that the cable is subject to attack by gnawing rodents i.e. mice, squirrels, gophers, etc. The gnawing rodents often chew through the cable, thereby causing a breach in the transmission of electrical current. Restoration of transmission requires location of the site of the breach and possibly digging the cable up before repairs can be made. This procedure is both costly and time-consuming.
Related art devices disclose means for providing rodent-gnawing protection for cables. Usually, the means comprises coiling protective wire(s) along the length of the cable and completely encompassing the cable. Although this arrangement affords protection from gnawing rodents, it greatly increases the weight while decreasing the flexibility of the cable. This increased weight and decreased flexibility play havoc with the cable installers' ability to transport and manipulate the cable.
The art would certainly welcome means for protecting cable that would restrict the cable's weight gain to a minimum while retaining an acceptable range of flexibility. Thus, a coiled-wire armored cable solving the aforementioned problems is desired.